Flame position and heat conduction responsive control



Sept. 24, 1963 J. K. LAMP, JR., ETAL 3,104,698

FLAME POSITION AND HEAT CONDUCTION RESPONSIVE CONTROL Filed Feb. 17, 1961 United States Patent 3,104,698 FLAME P01TEGN AND HEAT (ZONDUCTEON RESPONSWE CONTROL James K. Lamp, Jr., Newburgh, Ind, and Benjamin A. Phillips, Benton Harbor, Mich, assignors to Whirlpool Corporation, a corporation of Delaware Filed Feb. 17, 1951, Ser. No. 90,1l65 7 (llaiins. (Qi. 158-146) This invention relates to fuel burners and in particular to controls for fuel burners.

In the conventional absorption refrigerator, heat is deilvered to a solution of the refrigerant in a generator which commonly includes a tubular fire tube. A fuel burner is conventionally associated with the fire tube to provide a flarne within the fire tube as the source of heat energy of the generator. Such burners are conventionally of the Bunsen type wherein both primary arid secondary air are supplied to support the combustion of the fuel. The burner provides the time in the generator fire tube in a preselected arran ement wherein the flame is spaced inwardly from the Walls of the fire tube, conventionally slightly below the horizontal axis of the fire tube. Any of several abnormal conditions may cause the flame to deviate from the preselected arrangement in the fire tube to an undesirable abnormal arrangement. Thus, a reduced supply of air to the burner has been found to permit a transverse enlargement and/ or rising of the flame in the fire tube so that the upper portion of the flame is displaced toward the upper'wall of the fire tube. For example, any improper block-age Within the fire tube or associated flue, such as dirt or soot, will result in reduced air supply to the burner and cause a divergence of the flame. Such displacement, or rearrangement, of the flame is undesirable as incomplete combustion and reduced efliciency may result. The present invention is concerned with the prevention of such undesirable operation of the apparatus. Another condition which may cause undesirable operation is that of over-gassing, such as results.

from high fuel pressure or an oversize orifice within the burner. Yet another condition is that of misalignment or mislocation of any of the several components which would result in flame impingement. The present invention is also concerned with the automatic prevention of any of these undesirable operations.

Thus, a principal feature of the present invention is the provision of a new and improved control for a fuel burner.

Another feature of the invention is the provision of such a control arranged to detect a slightly abnormal arrangement of the flame, effectively positively precluding undesirable malfunctioning of the burner.

A further feature of the invention is the provision of such a control which further automatically discontinues operation of the burner upon an increase in thermal transfer to the control from the fire tube, such as by loss of fluid in the associated heat transfer means.

Still another feature is the provision of such a control providing automatic alignment of the burner with the fire tube and proper installation of the control in association therewith.

Other features and advantages will be apparent from the following description, taken in connection with the accompanying drawing wherein:

FIG. 1 is a plan view of a fuel burner provided with a control embodying the invention, in association with a fire tube;

FIG. 2 is a fragmentary diametric section taken substantially along the line 2-2 of FIG. 1;

'FIG. 3 is a fragmentary transverse section taken substantially along the line 3-3 of FIG. 1; and

ice

FIG. 4 is a fragmentary transverse section taken substantially along the line 44 of FIG. 1.

In the exemplary embodiment of the invention as disclosed in the drawing a Bunsen type burner generally designated 10 is shown to comprise a conventional gaseous fuel burner including a burner cap 11 atthe outer end of a mixing tube 12 received concentrically within an air shutter barrel 13. Fuel such as combustible gas is delivered to the mixing tube from a supply line 14, through a safety control 15, a conduit 16, a thermal control valve 17, burner body 18 and conduit 19. A lighter conduit 21 may be connected to the body 18 for providing combustible gas to the burner for igniting the same. Thermal control valve 17 includes a conductor strip 22 which projects from a bimetallic disk sensing element 23 to adjacent the path of the flame F extending from the burner cap 11 in the normal operation of the burner.

The bimetallic disk device 23 controls the operation of the valve 17 so that when a flame is present adjacent the strip 22 flow of combustible gas from the conduit to the burner body 18 is permitted. Thus, once a pilot flame is established by providing gaseous fuel from condui-t 21 to the burner, the thermal valve '17 automatically opens to provide the main fuel supply to the burner. Further, should the flame, for any reason, go out, the thermal valve automatically closes, preventing further operation of the burner until the flame is re-established.

Safety control 15 provides an improved, highly desirable further control of the burner 14). More specifically, control 15 includes a bimetallic disk device 24 selectively closing a valve 25 in response to a preselected elevation of temperature of the device 24. Heat energy is delivered to device 24 through a thermally conductive strip 26 suitably secured to a collar, generally designated 27. Collar 27, in turn, is disposed in heat transfer association with one end 23 of the fire tube 29 asin a convention-a1 generator G, being mounted over fire tube end 28, as best seen in FIG. 2. As shown in FIG. 2, collar 27 includes a first annular portion 30 defining an outer cylindrical recess 31 having a diameter substantially larger than the outer diameter of the fire tube end 28, an intermediate bore portion 32 having a diameter substantially equal to the outer diameter of ilue end 28 and having an upper portion 33 coincident with the upper portion of the recess 31, and an inner bore portion 34 having a diameter in alignment with the inner diameter of the fire tube 28-. A radial'shoulder 35 extends between bore portions 32 and 34 for abutment by the end surface 3-6 of the fire tube end 28. A locating pin 37 is fixed to the collar portion 30 to extend radially into recess 31 and into a corresponding hole 3-8 opening radially outwardly in the fire tube end 28. A wing bolt 39 is threaded through the collar portion 30 diametrically opposite pin 37 to retain the fire tube end 28, as shown in FIG. 2, in the collar portion 3% and with surface 36- abutting the collar surface 35.

The collar 27 further includes a second annular portion 40 through which bore 34 continues. The outer diameter of portion 40 is smaller than the outer diameter Olf collar portion 30. The collar portion 40 is defined by a chordal surface 41 against which strip 26 is facially secured for improved heat transfer therebetween. As best seen in FIG. 2, the collar is provided with a transverse slot 42 between collar portions 30 and 40, the slot extending substantially ci'rcum ferentially of the collar, or substantially fully through the upper half of the collar, thereby providing a thermal barrier between the upper half of collar portion 30 and the upper half of collar portion 40 to which the strip 26 is secured.

An arm 43 extends later-ally outwardly from collar portion 30 and is provided with a pair of posts 44 and 45 for supporting thermal control valve 17 and thus the other elements of burner 10, associated with the valve -17, as an integral assembly. The arm 43 is arranged to dispose the burner cap 11 in accurate preselected alignment with the fire tube end 28 when the fire tube end is disposed in the collar portion 30 as shown in FIG. 2 and as discussed above.

As best shown in FIG. 4, heat is transferred from fire tube 29 to collar 27 by means of an upper contact pad 50 and a pair of substantially diametrically opposed contact pads 51 and 52. These contact pads are created by re moving portions 53 of the inner wall Otf the first annular portion 36 of collar 27.

In operation, valve of safety control 15 is normally open to permit flow of the gaseous fuel to the burner. As long as the flame F is arranged in the preselected desired configuration, shown in full lines in FIG. 2, the safety control remains in this cnodition. However, should for any reason the flame F deviate from the desired preselected configuration, such as shown in dotted lines in FIG. 2, safety control '15 substantially immediately senses this deviation and prevents further operation of the burner, thereby effectively precluding improper combustion and reduced efiiciency as may result from such deviation of the flame. The deviation, or abnormality, of the flame P which causes operation of the safety control 15 is small, as heat may be transmitted to the annular ring portion 40' by radiation from the flame, convection thru the air currents, and/or conduction from fire tube 2.9 and collar 27.

It will be apparent that the transfer of heat from fire tube 29 to collar 27 thence to safety control 15 is somewhat limited. Thus, direct heat transfer between fire tube 2.9 and collar 27 is possible only through contact pads 50, 51 and 52, and the transverse slot 42 efiect-ively breaks the heat transfer path between the upper portions of first annular portion and second annular portion 40. This partial isolation of surface 41, to which strip 26 of the safety control 15 is attached, from the fire tube 29, permits the safety control to operate to extinglish the flame in another manner. Thus, flame F may deviate sufii ciently to transfer sufiicient additional heat by radiation from the flame to the ring portion 40, thus avoiding the conventional heat transfer path from the fire tube 29 to the collar 27.

This control device can also provide a safety function under conditions of proper flame conditions. Under uI1- usual circumstances wherein heat is not dissipated fromthe fire tube or tubular member 29' at a rate indicative of normal operation and overheating of the fire tube occurs, it is possible to effect sulficient heat transfer through the lower portion of the collar 27 to the collar portion 4! to activate the bimetallic disk 15 and terminate the supply of gas to the burner.

It will be apparent that safety control 15 may comprise an electrical thermostat attached to the ring portion 40. This electrical thermostat would energize or tie-energize, depending on established conditions, an electrical solenoid valve to control the supply of gas flow to the burner.

Thus the present invention comp-rehends an improved means for controlling a fuel burner which is extremely simple and economical of construction yet which effectively positively prevents undesirable incomplete combustion and inefficient operation.

Having described our invention as related to the embodiment shown in the accompanying drawing, it is our intention that the invention be not limited by any of the details of description, un ess otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claim-s.

We claim: 1

1. In an apparatus having a tubular member and a fuel burner adjacent one end of the tubular member providing a flame in a-preselected arrangement in the tubular member, a control comprising: means defining an entrance to the tubular member at said one end thereof; a valve for controlling the delivery of fuel to said burner; and thermo said preselected arrangement to an abnormal arrangement within the tubular member.

2. The apparatus of claim 1 wherein said entrance means comprises an annular element secured to said one end of the tubular member.

3. The apparatus of claim 1 wherein said entrance means comprises an annular element secured to said one end of the tubular member and including a portion axially spaced from said end of the tubular member and carrying said therrnoresponsive means.

4. The apparatus of claim 1 wherein said entrance means comprises an annular element secured to said one end of the tubular member and including means defining a thermal barrier for restricting heat transfer from a pre selected portion of the tubularmember to said themoresponsive means.

5. The apparatus of claim 1 wherein said entrance means further includes a portion supporting the burner in accurate alignment with the tubular member.

6. In an apparatus having a tubular member and a fuel her, a control comprising: means defining an entrance to the tubular member at said one end thereof; a valve for controlling the delivery of fuel to said burner; and a thermoresponsive means for selectively closing said valve when subjected to a preselected elevated temperature, said thermoresponsive means including sensing means in thermal transfer association with said entrance means and arranged to receive heat conducted from said tubular member and radiated from the flame within said tubular member to subject said thermoresponsive means to said elevated temperature whenever the flame deviates from said preselected arrangement to an abnormal arrangement within the tubular member.

7. In an apparatus having a tubular member and a fuel burner adjacent one end of the tubular member providing a flame in a preselected arrangement in the tubular memher, a control comprising: means defining an entrance to the tubular member at said one end thereof; a valve for controlling the delivery of fuel to said burner; and thermoresponsive means for selectively closing said valve when subjected to a preselected elevated temperature, said tlrermoresponsive means including sensing means in thermal transfer association with said entrance means and arranged to receive heat radiated from the flame to subject said thermoresponsive means to said elevated temperature whenever the dame deviates trom said preselected arrangement to an abnormal arrangement within the tubular member.

References Cited in the file of this patent UNITED STATES PATENTS 1,885,530 Mancib Nov. 1, 1932 2,271,449 Whitney Jan. 27, 1942 2,488,330 Robinson Nov. 15, 1949 2,524,377 Cunningham Oct. 3, 1950 2,761,667 Tiemann Sept. 4, 1956 2,852,241 Jackson Sept. 16, 1958 

1. IN AN APPARATUS HAVING A TUBULAR MEMBER AND A FUEL BURNER ADJACENT ONE END OF THE TUBULAR MEMBER PROVIDING A FLAME IN A PRESELECTED ARRANGEMENT IN THE TUBULAR MEMBER, A CONTROL COMPRISING: MEANS DEFINING AN ENTRANCE TO THE TUBULAR MEMBER AT SAID ONE END THEREOF; A VALVE FOR CONTROLLING THE DELIVERY OF FUEL TO SAID BURNER; AND THERMORESPONSIVE MEANS FOR SELECTIVELY CLOSING SAID VALVE WHEN SUBJECTED TO A PRESELECTED ELEVATED TEMPERATURE, SAID THERMORESPONSIVE MEANS INCLUDING SENSING MEANS IN THERMAL TRANSFER ASSOCIATION WITH SAID ENTRANCE MEANS AND ARRANGED TO SUBJECT SAID THERMORESPONSIVE MEANS TO SAID ELEVATED TEMPERATURE WHENEVER THE FLAME DEVIATES FROM SAID PRESELECTED ARRANGEMENT TO AN ABNORMAL ARRANGEMENT WITHIN THE TUBULAR MEMBER. 